I followed the link you posted and read the posts.
I've taken a look at the string table files and I don't see any problem translating them.
I think the issue is not the Hebrew text but the placements of the frames/divs on the page.
The test that should be made is editing the CSS of the primary layout and adding the attribute "direction: rtl" and see what happens and what breaks.
Regarding the different features of Zimbra:
- Using a Hebrew calendar is not a big issue since most (if not all) people using a computer are using a Gregorian calendar any way.
- Numbers and measures are standard Latin numbers and measures use the metric system.
- Time format preferred to be in a 24H format and not in 12H AM/PM
- Currency I don't know much about the mechanism that uses this type of data so can't comment on that. But if you can add a Chines Yen you can add Shekels
As I see it the only big issue is the actual UI layout (Menus, feature frames, tables, etc.)
All else can work as is.
Who knows, maybe its just a matter of editing the CSS with "direction:rtl" and it would be ok
Crossing fingers
Best regards,
Oranso.